Apparatus for sterile packing of sterile goods



Jan. 12, 1965 w. LC'JLIGER 3,164,935

APPARATUS FOR STERILE PACKING OF STERILE GOODS Filed Dec. 8, 1961 O 32 a 45 \j 1 E; 2 42 M 16 w I m alll {fix 627K021 Wu 4/ L 01 K7542.

. 3,164,936 APPARATUS F012 STERHLE PACKING OF STERELE GODDS Wiili Liiiiger, Konolfirigen, Switzerland, assignor to Alpura AG, Bern, Switzerland, a corporation of Switzerland Filed Dec. 8, H61, Ser. No. 158,172 Claims priority, application Switzerland Dec. 12, 1369 8 Claims. (Cl. 53-180) The invention relates to an apparatus for sterile packing of sterile goods wherein a flexible web is guided into a filling and packing machine and is formed therein into 1:; tube which is partly filled with the goods to be packed and, by being compressed transversely of its length, formed into closed filled receptacles, heating means for sterilizing the inside of the tube being provided inside the tube above the introduced goods.

Apparatus of this kind do not require sterilization of the weblike packing material before the tube is shaped. The entire tube forming, fillingand packing procedure is therefore considerably simplified as compared with a procedure. wherein the Web is sterilized before being introduced into the machine and a sterile atmosphere must be maintained while the material travels into the machine, and until the closed package is formed. This is accomplished, for instance, by maintaining a sterile atmosphere at a slight positive pressure in a chamber surrounding the traveling Web and the parts'for forming the packages and filling the same.

To operate an apparatus in which means for sterilizing the inner tube wall are provided inside the tube, any parts which are inside the tube and are not sterilized by the heating means in the tube, such as a pipe for introducing the goods to be packed, means for controlling the level of the goods filled into the tube and so on, must be initially sterilized before the tube and package forming and the filling operations are started. It is an object of the invention to facilitate and perform simply and reliably such initial sterilization.

1 Another object of the invention is to ensure reliable maintenance of sterile operating conditions at the changeover from initial sterilization to normal operation of the machine and to preclude any subsequent infection by germs which penetrate from the outside during operation.

According to the invention, a tubular jacket is disposed coaxially of the tube from which the containers United States Patent are made'and extends around at least those parts of the means for supplying a heat carrier to the interior of the jacket for initial sterilization of the interior of the jacket and parts located therein.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of one embodiment thereof when read in'connection with the accompanying drawing which is a longitudinal sectionfthrough an apparatus according to the invention.

Thefilling and packing machine illustrated, by way of example, in the drawing comprises a casing 1 supporting a column 2. A Web 5 of paper coated on one side with a plastic, such as polyethylene, is drawn continuously off a reel, not shown, and supplied to the packing machine and is guided in a ring 3 so as to form a tube 5, the coated side ofthe web forming the inside wall of the tube. The side. edges of the web 5 overlap one another. A heating pad 7 secured to a support 6 bears against the overlapped parts-of the web 5 for connecting 3,164,936 Patented Jan. 12, 1965 the parts by welding. A roller, not shown, is provided inside of the formed tube adjacent to the overlapped parts and opposite the heating pad 7 for effecting contact between the heating pad and the web. The pad 7 is electrically heated. Electrically heated pressing jaws 10 and 11 secured to endless chains 12 and 13, respectively, and traveling therewith when the apparatus is in operation are provided inside the casing 1. The chain 12 runs over guide wheels 14, 15, while the chain 13 runs over guide wheels 16, 17, the Wheels 14 and 17 or the wheels 15 and 16 being adapted to be rotated, by drive means which are not shown, to move the chains in the direction indicated by arrows 18 and 19. Other pairs of pressing jaws, not shown, are operative perpendicularly to the plane of the drawing so that the tube 5', which continuously moves in downward direction, is alternately compressed in two directions perpendicularly to one another. The movement of whichever pressing jaws engage the tube 5' imparts a downward drive on the tube while closed receptacles 20 are formed. The goods to be packed, for instance sterilized milk, are supplied to the apparatus through a pipe 21 supported by the column 2 in a manner described hereinafter. The supply of milk is so controlled by means of a fioat 9- that a constant liquid level 22 is maintained within the tube 5'.

A heating device is disposed inside the formed tube 5' above the introduced goods and surrounds the filling pipe 21. The heatingdevice comprises an electric heating coil 24 inside a quartz cylinder 25. The pipe 21 is protected against excessive heating by heat insulation 26. The heating coil 24 is connected to an electric cable 27 which extends to the outside of the tube 5'.

According to the invention, a jacket tube .28 is disposed coaxially of the tube 5' and substantially coextensive with the heating device and with the endportion of the filling pipe 21. When the device is in normal operation the jacket tube. 28 forms an annular space 29 with the tube 5'. The jacket tube 28 is provided with apertures 30 surrounded by an annular distributing duct 31 connected to a pipe 32. Since the jacket tube 28 extends into the operating range of the pressing jaws 10 and 11, the lower part of the tube 28 is made flexible, a hose 2311. being connected to a socket 28c which is screwed to the upper part 28a of the tube 28. The hose 28b is preferably made of a heat-resistant plastic such as a polymerization product of tetrafluoroethylene.

Above the heating device is a closure member 33 which, when the apparatus is in operation, bears against the inner wall of the tube 5'. A ring 34 secured to the filling pipe 21 supports the heating device and holds it against the closure member 33 which is secured to the pipe 21 by a clamping screw 35. A spring 23 is provided between the'heating device and the closure member 33 to allow for differences in expansion. Between the closure member 33 and the open upper end 36 of the tube 5 the pipe 21 is surrounded by an insulating jacket 37 which extends out of the top of the tube 5' and which is secured to the pipe 21. The closure member 33 is circular, coaxial with the pipe 21 and has a top surface formed with a cavity 38 for collecting water condensed on the pipe 21. The jacket 37 is'connected by a bracket 4 ,to the column 2 and supports the pipe 21 which is connected to the jacket 37.

I The pipe 32 is connected through a valve 43 to-a pipe 42 which is connected to a fan 44 blowing ambient air" into the pipe 42. Disposed in the pipe 42 is a heating device, for instance, in the form ofan electric heating from the atmosphere. With the illustrated arrangement 3 the pipe 32 can be supplied selectively either with hot sterile air or with sterile air of, for example, room temperature upon switching off of the heater 45. The pipe 42 is also connected to the filling pipe 21 by a pipe 49 provided with a valve 50.

Prior to starting normal operation the apparatus is initially sterilized by supplying heated sterile air through the pipe 32 to the space surrounded by the jacket tube 28 for sterilizing parts inside the jacket tube 28, such as the outside of the end portion of the filling tube 21, the annular support member 34, and the float device 9. The heated air may be at a temperature of, for instance, 300 C. Some of the air heated by the heater 45 is supplied to the filling pipe 21 for sterilizing the latter. The heating device 24, 25 may be switched on at this time, preferably at a low heating rate.

Once it is absolutely certain that all those parts which will subsequently be inside the tube 5' have sterile surfaces, the heater 45 is switched otf so that air which is at room temperature but sterile enters the pipe 32 and the filling tube 21. The cool sterile air supplied to the inside of the jacket tube 23 leaves the latter through its bottom and through the annular space between the closure member 33 and the top of the jacket tube to form barrier streams which prevent the entry of external air and reinfection of the parts which have previously been sterilized in the manner described.

Thereupon the heating coil 24 is switched on or current supply is brought up to full load, the heating pad 7 is switched on and the web 5 is introduced in an appropriate manner and pushed downwards between the closure member 33 and the jacket tube 28 until the web is engaged by the jaws 10, 11 whereupon the web is advanced by the action and movement of the jaws. The overlapping side edges of the web are welded together to form a lengthwise seam. The resultant tube 5' moves down, is closed by compression transversely of its axis by the pressing jaws and is simultaneously welded. The tube 5' now communicates with external atmosphere only by way of its aperture 36.

The heating power of the heating coil 24 is so adjusted, for instance, that the inside of the tube 5' passing along the coil 24 is heated to about 200 C. or more and thus continuously sterilized. Since all the surfaces which are now inside the tube 5' have been sterilized by the initial sterilization and since any germs on the inner tube wall are destroyed as the tube passes by the heating device, it is certain that the packages, which have provisionally been filled with sterile air, have a sterile interior. Sterility in the space below the heating device 24, 25 is further improved because the parts in said space remain at a high temperature after the initial sterilization until the first closure of the tube 5' by the jaws 10, 11. Thereuponthe valve 50 is closed and the valve 51 in the filling pipe 21 is opened and, instead of sterile air, the sterile substance to be packaged, for example .milk, is introduced. The closed packages now produced by the jaws 10, 11 are completely filled with milk.

The supply of sterile air at about room temperature through the pipe 32 into the space between the jacket tube 28 and the tube 5' may be continued to cool the outside of the tube. If the web of packing material used to form the tube 5' is sufficiently heat-resistant, however, this supply of cooling air can be omitted. If the supply of cooling air is maintained, effective cooling is provided because the narrow space between the tube 5' and the jacket tube 28 causes the air to flow at a relatively high speed ensuring a satisfactory heat transfer.

In addition to providing efficient initial sterilization, the jacket tube 28 serves as a guide when the web 5 is introduced into the apparatus.

The closure means 33 substantially precludes entry of non-sterile ambient air into the tube 5' when the apparatus is in operation. The air in the tube 5 is heated by the heating device 24, 25 and tends to flow away upwards. If no closure member 33 were provided, relatively cool air might penetrate from the outside into the tube 5'. Such relatively cool outside air is not sterile; if it descends at any speed it may not stay near the heating device 24, 25 long enough to destroy the germs contained in the outside air. The heating device operates as a radiant heater and relatively slowly heats the air which does not contact the quartz tube 25. The closure member 33 equalizes the temperature distribution in the tube 5 because it prevents change of the air in the tube 5 below the closure member 33.

The prevention of entry of ambient air into the tube 5 has another advantage. As a rule, the web 5 is coated with a synthetic substance, such as polyethylene, on the side which forms the inside wall of the finished packings. Polyethylene tends to oxidize in the presence of oxygen and at high temperatures whereby its desirable properties, more particularly its weldability, are impaired. The air which is initially present in the interior of the tube 5 below the closure member 33 becomes oxygen-depleted fairly rapidly in operation so that detrimental oxidation can be substantially precluded by preventing entry of fresh air.

It moist ambient air comes in contact with the filling pipe 21, condensate may be formed thereon. To avoid condensation the pipe 21 is surrounded by a heat insulation above the closure member 33. In the illustrated embodiment such insulation is in the form of a jacket 37, theair space within such jacket forming an effective heat insulation. Any condensate which nevertheless may flow down on the tube 21 is collected in the cavity 38 on top of the closure member 33 and, if required, can be removed through a suitable drain duct. In this way entry of non-sterile condensate forming on the outer surface of the tube 2.1 into the tube 5 is avoided.

The invention is not limited to the illustrated embodiment. The illustrated apparatus can be used to fill and pack flowable goods other than milk.

I claim" 1. In apparatus for sterile packing of sterile goods comprising means for continuously forming a vertical tube from a flexible web, means for advancing and compressing said tube transversely of the length of the tube for closing the tube, means extending into said tube for filling the sterile goods into the tube above said compressing means, and heating means placed inside said tube below said tube-forming means and above the goods filled into the tube for heating and sterilizing the inside of the tube, said fillng means extending through and having a part extending below said heating means toward said compressing means:

a vertical tubular element placed concentrically around said formed tube and having an upper end vertically spaced from and located below said means for forming said vertical tube from a-flexible web,

said tubular element having a lower end vertically spaced from and placed substantially below said heating means and adjacent said tube advancing and compressing means, and

means connected to said tubular element for conducting a heat carrier thereinto for initially sterilizing the interior of said tubular element and said part of said filling means extending below said heating means prior to starting formation and filling of said tube.

2. In an apparatus for sterile packing of sterile goods comprising means for continuously forming a vertical tube from a flexible web, means for advancing and compressing said tube transversely of the length of the tube for closing the tube, means extending into said tube for filling the sterile goods into the tube above said compressing means, and heating means placed inside said tube below said tube-forming means and above the goods filled into the tube for heating and sterilizing the inside of the tube, said filling means extending through and having a part extending below said heating means toward said compressing means:

said formed tube and having an upper end vertically spaced from and located below said means for forming said vertical tube from a flexible web,

said tubular element having a lower end portion made of flexible material and having a lower end vertically spaced from and located. substantially below said heating means and converging toward and being adjacent to the formed tube, and means connected to said tubular element for conducting a heat carrier thereinto for initially sterilizing the interior of said tubular element and said part of said filling means extending below said heating means prior to starting formation and filling of said tube. 3.- In an apparatus for sterile packing of sterile goods comprising means for continuosly forming a vertical tube from a flexible Web, means for advancing and compressing said tube transversely of the length of the tube for closing the tube, means extending into said tube for filling the sterile goods into the tube above said cornpressing means, and heating means placed inside said tube below said tube-forming means and above the goods filled into the tube for heating and sterilizing the inside of the tube, said filling means extending through and V spaced from and placed substantially below said heating means and adjacent said tube advancing and compressing means, and

means connected to said tubular element for selectively conducting a heat carrier thereintofor initially steri- 7 e heat carrier to said jacket tube for initially heating and sterilizing the interior of said jacket tube and at least the part of said filling means extending beyond said heating means toward said compressing means prior to starting formation and filling of said formed tube, and p circular closure member coaxially of and substantially at the end of saidjacket tube averse of said compressing means, the diameter of said closure member being substantially equal to the inside diameter of said formed tube.

5. In an apparatus according to claim 4 wherein said filling means includes a pipe having a portion coaxial of said formed tube and extending through said heating means, said closure'member being placed at the end of said heating means averse of said compressing means and being connected to said pipe. i

6. In an apparatus according to claim 5 wherein said pipe has a part extending into said formed tube beyond the end of said heating means which end is averse of said compressing means, and a heat insulating means surrounds saidpart of said pipe.

7. In an apparatus for sterile packing of sterile goods comprising means for continuously forming a vertical lizing said part of said filling means extending below said heating means prior to starting formation and filling of said tube, and for conducting a coolant into said tubular element for cooling the outside of the formed tube when the apparatus is in tube-forming and filling operation. I

4. In an apparatus for sterile packing of sterile goods comprising means for continuously forming a tube from a flexible web, means for'advancing and compressing said tube transversely of the length ofthe tube for closing the tube, means extending into said tube for filling the sterile" goods into the tube upstream of said compressing means, and heating means placed inside said tubeupstream of the goods 'filled into the tube with respect to the movement of the tube for'heating and sterilizing the inside of the tube, said fillingmeans extending through and having;

a part extending beyond said heating means toward said i means connected to said jacket tube for supplying a tube from a flexible web, means for advancing said tube in downward direction and compressing said tube transversely to the length or" the tube for closing the tube, heating means placed inside said tube and terminating above and in spaced relation from said compressing means for heating and sterilizingthe inside of said tube, and filling means for filling the'goods into said tube and having a part placed in the space between said heating means and said compressing means, said filling means including a pipe extending into said tube and having a portion coaxial of said tubeand terminating adjacent to said compressing means: a v a jacket tube placed around said formed tube andhaving a diameter at least as great as the outside diameter of said tube, said jacket tube being permanently open at both ends and being substantially coextensive with said heating means and the entire space between saidheating means'iand said compressing means,

means connected to said jacket tube for introducing a heat carrier into said jacket tube for initially sterilizing the interior of said jacket tube and at least the part of said filling means between said heating means and saidcornpressing means prior to starting forming and filling said formed tube, and

circular closure member placed 'coaxially of said formed tube above said heating means and connected to said pipe, the diameter of said closure member being substantially equal to the inside diameter of closure member has a top surface and a cavity in said top surface for collecting water condensed on said pipe above said closure member.

References Cited in the file of this patent 3,086,336 Rausing et al Apr. 23, 1963 

4. IN AN APPARATUS FOR STERILE PACKING OF STERILE GOODS COMPRISING MEANS FOR CONTINUOUSLY FORMING A TUBE FROM A FLEXIBLE WEB, MEANS FOR CONTINUOUSLY FORMING A TUBE FROM TUBE TRANSVERSELY OF THE LENGTH OF THE TUBE FOR CLOSING THE TUBE, MEANS EXTENDING INTO SAID TUBE FOR FILLING THE STERILE GOODS INTO THE TUBE UPSTREAM OF SAID COMPRESSING MEANS, AND HEATING MEANS PLACED INSIDE SAID TUBE UPSTREAM OF THE GOODS FILLED INTO THE TUBE WITH RESPECT TO THE MOVEMENT OF THE TUBE FOR HEATING AND STERILIZING THE INSIDE OF THE TUBE, SAID FILLING MEANS EXTENDING THROUGH AND HAVING A PART EXTENDING BEYOND SAID HEATING MEANS TOWARD SAID COMPRESSING MEANS; A JACKET TUBE PLACED AROUND SAID FORMED TUBE AND HAVING A DIAMETER AT LEAST AS GREAT AS THE OUTSIDE DIAMETER OF SAID FORMED TUBE AND BEING AT LEAST COEXTENSIVE WITH THE ENTIRE PART OF THE APPARATUS BETWEEN SAID HEATING MEANS AND SAID COMPRESSING MEANS, SAID JACKET TUBE BEING ALSO SUBSTANTIALLY COEXTENSIVE WITH SAID HEATING MEANS, MEANS CONNECTED TO SAID JACKET TUBE FOR SUPPLYING A 